Coke oven flue gas electromigration desulfurization process for sulfur production

Abstract

The invention discloses a process for preparing sulfur by performing electro-migration desulfurization on coke oven flue gas, and belongs to the energy-saving environmental-protection field of the coking industry. The process comprises the following steps: leading coke oven flue gas from a coke oven horizontal flue into a sulfur dioxide electro-migration film separator to separate to obtain SO2-rich gas and SO2-removed flue gas, leading SO2-removed flue gas into a heater to heat, feeding the heated flue gas into an SCR denitration reactor to complete denitration, recycling waste heat of denitrated flue gas, feeding the denitrated flue gas into a chimney to exhaust; feeding the SO2-rich gas and H2S-rich gas from a hydrogen sulfide analytical tower into a Claus oven to react to generate Claus tail gas containing sulfur steam, leading the Claus tail gas containing sulfur steam into a sulfur condenser to cool and recycle sulfur, dividing the cooled Claus tail gas into three parts, whereinone part enters the tail gas cooling section of the Claus oven to exchange heat and heat up, and enters the hydrogen sulfide analytical tower as a stripping gas source and a heat source of an H2S analytical tower, another part is subjected to dust removal, then enters the sulfur dioxide electro-migration film separator as electro-migration sulfur-removal carrier gas of the coke oven flue gas, andthe rest part enters a coke oven crude gas pipe network. The process can effectively recycle sulfur pollutants in the coke oven flue gas.

Description

technical field [0001] The invention relates to desulfurization of coke oven flue gas and recycling of sulfur resources, belongs to the field of energy conservation and environmental protection in the coking industry, and specifically relates to a process for producing sulfur by electromigration desulfurization of coke oven flue gas. Background technique [0002] At present, coke oven flue gas desulfurization and denitrification processes operating in China: semi-dry desulfurization + low-temperature SCR selective catalytic reduction denitrification and dust removal integrated process, desulfurization and denitrification integrated technology (activated coke method), moving bed dry desulfurization + low-temperature SCR Denitrification technology, new catalytic flue gas desulfurization and denitrification technology, ammonia desulfurization + ozone oxidation denitrification technology all adopt the process technology of desulfurization first and then denitrification. Although ...

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Problems solved by technology

[0003] Choose the layout method of desulfurization first and then denitrification. The dry and semi-dry desulfurization process can be configured with SCR denitrification process. If the enterprise chooses the wet desulfurization process, there are two options for the current technology: one is after being treated by the desulfurization device. The flue gas temperature is 60-80°C. First, the flue gas temperature is raised to above 180°C through the heat exchange device, and then enters the flue gas SCR denitrification device for treatment. This solution is not advisable in terms of energy consumption, and it is also not advisable in terms of economy. of

The second scheme is wet desulfurization process + ozone oxidation denitrification process. This scheme can not only meet the arrangement sequence of desulfurization first and then denitrification, but also effectively remove SO in flue gas pollutants. 2 , NOx control is within the qualified range, but so far there is no successful operation case report

[0005] Shaanxi No. 1 coking plant adopts SCR denitrification + ammonia desulfurization process. The denitrification device has not been able to operate continuously and stably. The problem of continuous and stable operation caused by the arrangement of the denitrification device at the front end of the desulfurization device has always plagued the company.

[0008] (1) In the existing coke oven flue gas SDA+SCR desulfurization and denitrification process, the desulfurization by-products are solid wastes, which cannot be used as resources and cause secondary pollution to the environment;

[0009] (2) The existing coke oven flue gas SDA+SCR desulfurization and denitrification process, the desulfurization process is a semi-dry method, the system is frequently blocked, and the operation stability is poor;

[0010] (3) The existing coke oven flue gas carbon-based catalytic desulfurization combined with SCR denitrification process, although the by-product of desulfurization is low-concentration dilute sulfuric acid, and the sulfur pollutants have been recycled and utilized, but its utilization value is low, and it needs to be further concentrated or combined with Concentrated sulfuric acid mixed

At the same time, during the denitrification process, the flue gas heats up and consumes a lot of energy, resulting in large investment and high operating costs for desulfurization and denitrification.

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